All these currencies may not have such a great potential to be honest, doge might be an exception in that last though.  EMC should be pumped anytime soon, so you can invest in it more than your normal one, but you better be careful on the timing. THC, it was pumped because of the partnership with Wiz Khalifa, not sure on whether it's worth the investment now as it and already got pumped by whales. Other altcoins, I can't provide much info on it, as I choose altcoins based on my own research and other various factors.